Uncovering the Molecular Mechanisms that Underlie Photoperiodic Control of Plant Growth

了解植物对不断变化的环境条件的反应机制对改善农业至关重要。植物生长对日照长度的季节性变化有响应，然而，我们对参与这种光周期控制生长的因素的理解是不完整的。本研究旨在研究一种新发现的蛋白的功能，该蛋白是植物生长对光周期反应的关键调节因子。从这项工作中获得的知识将为理解将光传感、日长测量和多种条件下的生长联系在一起的机制提供有价值的见解。这些信息将有助于我们更好地预测植物对环境的反应。该提案还将支持开发和分发基于树莓派微型计算机系统的低成本、开源植物成像平台给高中，作为将科学带入当地社区的努力的一部分。这种“更广泛影响”活动的一个好处是，公众有可能开发创新系统，对植物生长进行持续、自动化的监测。这项工作将改变我们了解植物对环境季节性变化的反应的能力，有助于实现改善农业的长期目标。该项目的目的是了解在变化的光周期条件下，光信号与生物钟耦合调节生长的分子机制。该项目将研究与生物钟相关的光信号通路的调节因素，以光周期依赖的方式调节生长以响应环境。利用亲和纯化和质谱法鉴定生物钟相关成分，发现了一种直接结合时钟和光信号因子的新蛋白，命名为mass SPEC identified modulation GROWTH FACTOR 1 （MMF1）。MMF1是一种保守的，植物特异性的，核定位的因子，以特定的方式调节下胚轴的伸长。本研究旨在通过结合生理学、遗传学、生物化学、质谱分析和表达分析，确定MMF1调节植物生长反应的机制，全面了解MMF1在植物中的作用。基于质谱分析结果、直接相互作用分析、遗传学、下胚轴伸长分析和基因表达分析的初步数据表明，MMF1在以日长依赖的方式调节生长中起关键作用。本提案的目的是1)确定MMF1在光和光周期依赖的方式下调节生长和生理的作用，2)确定特定环境条件下MMF1调节光信号通路的遗传和生化基础，以及3)确定MMF1在调节光信号通路下游基因表达网络中的作用。从这项工作中获得的知识将为理解光信号，生物钟和多种条件下生长的耦合机制提供有价值的见解。这些信息将有助于更好地预测植物对环境的反应和确定遗传靶点以提高农业生产力。拟议的研究将通过PI参与正在进行的科学推广和丹佛斯植物科学中心的REU项目以及圣路易斯华盛顿大学的预约，为中学，本科，研究生和研究生水平的学生提供科学培训和教育机会。此外，一个廉价的延时成像系统将与教育材料相结合，分发给当地的高中，以培养对植物对环境反应的兴趣。通过组装、编程并将这些低成本、开源的植物成像系统整合到课堂上的科学项目中，当地学生将获得参与STEM活动的独特机会。此外，与公众合作有潜力开发创新和分布式传感器系统，用于非侵入性监测植物生长。总之，拟议的研究将通过更好地了解不同物种的生物钟功能，并通过参与教育和培训计划增加公众的参与，对社会产生重大影响。

Understanding the mechanisms underlying plant responses to changing environmental conditions is critical to improving agriculture. Plant growth is responsive to seasonal changes in day length, however, our understanding of factors that participate in this photoperiodic control of growth is incomplete. This proposal aims to investigate the function of a newly identified protein that is a key regulator of plant growth in response to photoperiod. The knowledge gained from this work will provide valuable insight into understanding the mechanisms that tie together light sensing, day length measurement, and growth under multiple conditions. This information will contribute to our ability to better anticipate plant responses to the environment. This proposal will also support the development and distribution of a low-cost, open-source plant-imaging platform based on Raspberry-Pi microcomputer systems to high schools as part of an effort to bring science into the local community. A benefit from this Broader Impacts activity is the potential for the public to develop innovative systems for continual, automated monitoring of plant growth. This work will transform our ability to understand plant responses to seasonal changes in the environment, contributing to the long-term goal of improving agriculture. The objective of this project is to understand the molecular mechanisms that couple light signaling with the circadian clock to regulate growth under changing photoperiodic conditions. This project will investigate the factors that modulate light signaling pathways in association with the circadian clock to regulate growth in response to the environment in a photoperiod-dependent manner. Using affinity purification and mass spectrometry to identify circadian clock-associated components, a new protein was identified that directly binds to both clock and light signaling factors, named MASS SPEC IDENTIFIED MODULATING GROWTH FACTOR 1 (MMF1). MMF1 is a conserved, plant-specific, nuclear-localized factor that regulates hypocotyl elongation in a day-length specific manner. This study aims to determine the mechanisms by which MMF1 modulates growth responses by combining physiology, genetics, biochemistry, mass spectrometry, and expression analysis to gain comprehensive understanding into the role of MMF1 in plants. Preliminary data, based on mass spectrometry results, direct interaction assays, genetics, hypocotyl elongation assays, and gene expression analysis, suggest a key role for MMF1 in modulating growth in a day-length dependent manner. The aims of this proposal are to 1) determine the role of MMF1 in the regulation of growth and physiology in a light- and photoperiod-dependent manner, 2) identify the genetic and biochemical bases underlying MMF1 modulation of light signaling pathways under specific environmental conditions, and 3) determine the role of MMF1 in regulating gene expression networks downstream of light signaling pathways. The knowledge gained from this work will provide valuable insight into understanding the mechanisms that couple light signaling, the circadian clock and growth under multiple conditions. This information will contribute to the ability to better anticipate plant responses to the environment and identify genetic targets to manipulate for increased agricultural productivity. The proposed research will provide scientific training and educational opportunities for students at the secondary school, undergraduate, graduate and post-graduate levels through the PI's participation in on-going science outreach and REU programs at the Danforth Plant Science Center and an appointment at Washington University in St. Louis. Also, an inexpensive time-lapse imaging system will be combined with educational materials for distribution to local high schools to cultivate an interest in plant responses to the environment. Through assembling, programming, and incorporating these low-cost, open-source plant-imaging systems into science projects within the classroom, local students will gain a unique opportunity to participate in STEM activities. Moreover, working with the public has the potential to develop innovative and distributive sensor systems for the non-invasive monitoring of plant growth. Together, the proposed research will have a significant impact on society through a better understanding of circadian clock function in diverse species and increased engagement with the public through participation in education and training programs.